From swine flu to infections in primary care

S S Lee 李瑞山

HK Pract 2009;31:49-50

When this editorial goes to press, the 'swine' flu (termed "Influenza A (H1N1)" by World Health Organization) virus must have already found its way to most corners of the inhabited world.¹ Responding to the situation, medical professionals and their allies are making concerted efforts at all fronts. Over the last weeks, we witnessed snapshots of hospital specialists making preparation for a potential influx of patients, public health agencies implementing control measures, and medical scientists tracking down the virus. The role of family doctors is more varied, ranging from advising their patients on precautions for travels, need for vaccination, effectiveness of medicine like tamiflu, and indications for diagnostic testing. The demand on knowledge and clinical skills is more diverse than that for an infectious disease specialist.

The efforts of family doctors in an influenza outbreak reflect a continuum from primary care, to clinical management and to public health practice. In this issue, Chiu KC et al provides an overview of issues, implicated in the prevention and control of influenza, albeit narrowly focused on elderly people in institutions.² We are reminded that influenza has the propensity to spread in vulnerable communities. The ageing population in Hong Kong obviously constitutes one sizable group with defective host immunity who are prone to the development of complications. This timely study highlights the importance of surveillance, case finding and a coordinated approach to outbreak management. Chemoprophylaxis and vaccinations are necessary but insufficient to control the spread of the outbreaks. The title of their report is self explanatory, which serves to underline the importance of both "non-pharmacological" and "pharmacological" interventions.³ It can be argued that Chiu's results are only applicable in the unique setting of an institution with relatively less mobile individuals, which may be different from that in the community at large. The principles shall in fact be no different, as illustrated by lessons learned from the current swine flu epidemic. The monitoring of influenza-like illness (ILI) at clinic level clearly forms part of a syndromic surveillance system useful in alerting the community of any impending outbreaks.⁴ Case detection is a more complex measure at a family doctor's clinic versus an elderly home. Interestingly it is as much a public health term as a primary care tool, the latter referring to exploration of behaviours and early symptoms useful in supporting a clinical diagnosis. In this connection, travel history, hygiene practice and potential history of exposure are crucial in history-taking. Clinical management again involves pharmacological as well as non-pharmacological means. The non-pharmacological armamentarium of a family doctor includes professional advice on health maintenance and disease control.

Influenza is but one example of the whole range of infections that family doctors need to manage professionally in the community. Clinical skills for managing infections stem from the theoretical framework of exposure - infection - disease, which is applicable to acute and chronic infections alike. For any infection, a family doctor is uniquely positioned to contribute by not just minimizing exposure, but also combating infection as well as reducing the development of clinical disease (including complications). HIV infection is a case in point. With advances in treatment, the crux of effective intervention now rests with early detection. In clinical HIV management, the reduction of morbidity and mortality after antiretroviral therapy (coined "highly active antiretroviral therapy", or HAART) is phenomenal. Such clinical gains come in line with the suppression of viral load which may reduce the risk of spread on a population level. These benefits would not be realized if HIV positive patients are unidentified. It is clear that exploration of behavioural practice provides the entry point to effective intervention. In the management of patients known to be living with HIV, again there are more issues than just HAART. Not unlike the management of chronic diseases, a holistic approach is crucial in order that such co-morbid conditions as hyperlipidaemia, hypertension and diabetes, and potential drug interaction, are dealt with through the collaboration of HIV physicians and the patient's family doctor.⁵ It would not be difficult to find the equivalent roles of family doctors in the management of tuberculosis, sexually transmitted infections, childhood infections, and the different forms of viral hepatitis.

A poorly appreciated area in infectious disease management is infection control practice. Infection control does not refer simply to hygiene practice but the provision of a safe environment in health setting. Chiu's study reported that "the (influenza) vaccination rate of staff was 50%". This is an unacceptably low figure. Some health care workers are concerned about effectiveness and even safety of the influenza vaccine.⁶ It's not uncommon to hear such comments as "I received vaccine last year and still fell sick with flu", reflecting an attitude which needs to be rectified. Obviously the yearly influenza vaccine can only protect a person from the virus strains which are presumably in circulation. Many health care workers may not however be aware of the main objective of receiving influenza vaccination in public health context. Rather than self-protection, vaccination of health care workers (doctors, nurses, and other clinical staff) serves to reduce the risk of introducing the virus in the health care setting. Influenza vaccination of health staff, including family doctors and their clinic staff, is an infection control practice that needs to be adhered to, with good coverage. Let's be reminded that the dynamic role of family doctor does not begin and end with patients, but includes him/herself, in accordance with the medical principle of "first do no harm". Every effective public health strategy begins from home. Likewise influenza control begins from universal vaccination of health care workers, including family doctors, as a key infection control strategy.